1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/LibOVR/Src/Kernel/OVR_System.h	Wed Jan 14 06:51:16 2015 +0200
     1.3 @@ -0,0 +1,174 @@
     1.4 +/************************************************************************************
     1.5 +
     1.6 +PublicHeader:   OVR
     1.7 +Filename    :   OVR_System.h
     1.8 +Content     :   General kernel initialization/cleanup, including that
     1.9 +                of the memory allocator.
    1.10 +Created     :   September 19, 2012
    1.11 +Notes       : 
    1.12 +
    1.13 +Copyright   :   Copyright 2014 Oculus VR, LLC All Rights reserved.
    1.14 +
    1.15 +Licensed under the Oculus VR Rift SDK License Version 3.2 (the "License"); 
    1.16 +you may not use the Oculus VR Rift SDK except in compliance with the License, 
    1.17 +which is provided at the time of installation or download, or which 
    1.18 +otherwise accompanies this software in either electronic or hard copy form.
    1.19 +
    1.20 +You may obtain a copy of the License at
    1.21 +
    1.22 +http://www.oculusvr.com/licenses/LICENSE-3.2 
    1.23 +
    1.24 +Unless required by applicable law or agreed to in writing, the Oculus VR SDK 
    1.25 +distributed under the License is distributed on an "AS IS" BASIS,
    1.26 +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    1.27 +See the License for the specific language governing permissions and
    1.28 +limitations under the License.
    1.29 +
    1.30 +************************************************************************************/
    1.31 +
    1.32 +#ifndef OVR_System_h
    1.33 +#define OVR_System_h
    1.34 +
    1.35 +#include "OVR_Allocator.h"
    1.36 +#include "OVR_Log.h"
    1.37 +#include "OVR_Atomic.h"
    1.38 +
    1.39 +namespace OVR {
    1.40 +
    1.41 +
    1.42 +//-----------------------------------------------------------------------------
    1.43 +// SystemSingleton
    1.44 +
    1.45 +// Subsystems are implemented using the Singleton pattern.
    1.46 +// To avoid code duplication in all the places where Singletons are defined,
    1.47 +// The pattern is defined once here and used everywhere.
    1.48 +
    1.49 +class SystemSingletonInternal
    1.50 +{
    1.51 +    friend class System;
    1.52 +
    1.53 +    SystemSingletonInternal* NextSingleton;
    1.54 +
    1.55 +    // No copying allowed
    1.56 +    OVR_NON_COPYABLE(SystemSingletonInternal);
    1.57 +
    1.58 +protected:
    1.59 +    SystemSingletonInternal() :
    1.60 +        NextSingleton(0)
    1.61 +    {
    1.62 +    }
    1.63 +
    1.64 +    virtual ~SystemSingletonInternal(){}
    1.65 +
    1.66 +    // Call this to register the destroy events
    1.67 +    // Destroy callbacks will be called in the reverse order they were registered
    1.68 +    // Note: As a rule of thumb, call this at the end of the singleton class constructor.
    1.69 +    void PushDestroyCallbacks();
    1.70 +
    1.71 +    // Required: Invoked when the System object is shutting down
    1.72 +    // Called after threads are stopped
    1.73 +    // Called before Log, Allocator, and Timer subsystems are stopped
    1.74 +    // Listeners are called in the opposite order they were registered
    1.75 +    virtual void OnSystemDestroy() = 0;
    1.76 +
    1.77 +    // Called just before waiting for threads to die
    1.78 +    // Listeners are called in the opposite order they were registered
    1.79 +    // Useful to start terminating threads at the right time
    1.80 +    // Note: The singleton must not delete itself here.
    1.81 +    virtual void OnThreadDestroy() {}
    1.82 +};
    1.83 +
    1.84 +// Singletons derive from this class
    1.85 +template<class T>
    1.86 +class SystemSingletonBase : public SystemSingletonInternal
    1.87 +{
    1.88 +    static AtomicPtr<T> SingletonInstance;
    1.89 +    static T* SlowGetInstance();
    1.90 +
    1.91 +protected:
    1.92 +    ~SystemSingletonBase()
    1.93 +    {
    1.94 +        // Make sure the instance gets set to zero on dtor
    1.95 +        if (SingletonInstance == this)
    1.96 +            SingletonInstance = 0;
    1.97 +    }
    1.98 +
    1.99 +public:
   1.100 +    static OVR_FORCE_INLINE T* GetInstance()
   1.101 +    {
   1.102 +        // Fast version
   1.103 +        // Note: The singleton instance is stored in an AtomicPtr<> to allow it to be accessed
   1.104 +        // atomically from multiple threads without locks.
   1.105 +        T* instance = SingletonInstance;
   1.106 +        return instance ? instance : SlowGetInstance();
   1.107 +    }
   1.108 +};
   1.109 +
   1.110 +// For reference, see N3337 14.5.1.3 (Static data members of class templates):
   1.111 +template<class T> OVR::AtomicPtr<T> OVR::SystemSingletonBase<T>::SingletonInstance;
   1.112 +
   1.113 +// Place this in the singleton class in the header file
   1.114 +#define OVR_DECLARE_SINGLETON(T) \
   1.115 +    friend class OVR::SystemSingletonBase<T>; \
   1.116 +private: \
   1.117 +    T(); \
   1.118 +    virtual ~T(); \
   1.119 +    virtual void OnSystemDestroy();
   1.120 +
   1.121 +// Place this in the singleton class source file
   1.122 +#define OVR_DEFINE_SINGLETON(T) \
   1.123 +    namespace OVR { \
   1.124 +    template<> T* SystemSingletonBase<T>::SlowGetInstance() \
   1.125 +    { \
   1.126 +        static OVR::Lock lock; \
   1.127 +        OVR::Lock::Locker locker(&lock); \
   1.128 +        if (!SingletonInstance) SingletonInstance = new T; \
   1.129 +        return SingletonInstance; \
   1.130 +    } \
   1.131 +    }
   1.132 +
   1.133 +
   1.134 +// ***** System Core Initialization class
   1.135 +
   1.136 +// System initialization must take place before any other OVR_Kernel objects are used;
   1.137 +// this is done my calling System::Init(). Among other things, this is necessary to
   1.138 +// initialize the memory allocator. Similarly, System::Destroy must be
   1.139 +// called before program exist for proper cleanup. Both of these tasks can be achieved by
   1.140 +// simply creating System object first, allowing its constructor/destructor do the work.
   1.141 +
   1.142 +// TBD: Require additional System class for Oculus Rift API?
   1.143 +
   1.144 +class System
   1.145 +{
   1.146 +public:
   1.147 +    // System constructor expects allocator to be specified, if it is being substituted.
   1.148 +    System(Log* log = Log::ConfigureDefaultLog(LogMask_Debug),
   1.149 +           Allocator* palloc = DefaultAllocator::InitSystemSingleton())
   1.150 +    {
   1.151 +        Init(log, palloc);
   1.152 +    }
   1.153 +    ~System()
   1.154 +    {
   1.155 +        Destroy();
   1.156 +    }
   1.157 +
   1.158 +	static void OVR_CDECL DirectDisplayInitialize();
   1.159 +    static bool OVR_CDECL DirectDisplayEnabled();
   1.160 +
   1.161 +    // Returns 'true' if system was properly initialized.
   1.162 +    static bool OVR_CDECL IsInitialized();
   1.163 +
   1.164 +    // Initializes System core.  Users can override memory implementation by passing
   1.165 +    // a different Allocator here.
   1.166 +    static void OVR_CDECL Init(Log* log = Log::ConfigureDefaultLog(LogMask_Debug),
   1.167 +                               Allocator *palloc = DefaultAllocator::InitSystemSingleton());
   1.168 +
   1.169 +	// De-initializes System more, finalizing the threading system and destroying
   1.170 +    // the global memory allocator.
   1.171 +    static void OVR_CDECL Destroy();
   1.172 +};
   1.173 +
   1.174 +
   1.175 +} // namespace OVR
   1.176 +
   1.177 +#endif